Turbine pump



June 14, 1960 G. E. MosuRE 2,940,394

TURBINE PUMP Filed 001'.. 3, 1958 F IGA.

PUMP PRESSURE RISE RS I.

United States Patent O TURBINE PUMP Garrett E. Mosure, Sepulveda,Calif., assignor to West- Filed Oct. 3, 1958, Ser. No. 765,178

6 Claims. (Cl. 10S-2) This invention relates to rotary pumps of theturbine or regenerative type and has for an object to provide animproved pump of this type.

Turbine pumps have high pressure -developing capacity even at relativelylow speed, because of the recirculating action between the blades 'ofthe impeller and the walls of the pressure developing chamber, as wellas the resultant accumulation of energy in the fluid during its travelbetween the suction' inlet and discharge outlet. However, the maximumfuel flow (delivery) capacity of the pump isattained at relatively lowspeeds and may be insuicient for many applications.

In -view of the above, it is a further object to provide a. uid pumpofthe turbine type which has a high pressure developing capacity atrelatively low speeds and has a high fuel delivery capacity at higherspeeds.

Another object of the invention is to provide a duid pump of the turbinetype in which the Huid llow and fluid pressure developingcharacteristics of the pump are modified in response to a predeterminedspeed signal.

In accordance with the invention, there is provided a turbine pumphaving an impeller provided with a pair of annular rows of radial bladesand disposed within a housing which, jointly therewith, defines asymmetrical annual pressure developing chamber or passageway. The pumpis further provided with the usual peripherally spaced primary suctioninlet and primary discharge outlet for the pressure developing chamber.

A secondary suction inlet and a secondary discharge outlet are alsoprovided for the chamber and are disposed intermediate the primary inletand outlet. The secondary inlet and outlet are blocked in the low speedrange by valve structure, so that the pump operates in the conventionalmanner in the low speed range to deliver uid at adequate pressure and owrate.

Means responsive to speed of the impeller is provided for actuating thevalve structure to the unblocking position at a predetermined speedvalue. Accordingly, in the upper speed range, iiuid is admitted to thepressure developing chamber by the primary and secondary suction inletsand delivered therefrom at increased flow rate by the primary andsecondary discharge outlets. Since, in .the upper speed range, thelength of the duid path through the chamber is considerably reduced, thepressure developed by the fluid owing therethrough is considerably lessthan that developed by a conventional turbine pump in the same speedrange. However, since the pump inherently has excessive' pressuredeveloping capacity, the -developed pressure is more than adequate forpractical applications.

One of the most notable applications, for example, is in a gas turbineengine wherein the pump is driven by the engine rotor for supplyingliquid fuel thereto within prescribed pressure and flow rate ranges forcombustion purposes at varying rates' of speed (for example, from about1400 r.p.m. to 12,500 r.p.m.). In such an appliice cation, the speedresponsive means may be desirably adjusted to unblock the secondaryinlet and outlet of the pump at about 5000 r.p.m., which speed is theidling speed of the engine.

The above and other objects are eected by the invention as will beapparent from the following description taken in connection with theaccompanying drawings, forming a part of this application, in which:

Fig. l is a diagrammatic view illustrating a typical gas turbine enginehaving a fuel pump embodying the invention, the pump being shown in oneoperative' positron;

Fig. 2 is a View showing the pump in another operative position;

Fig. 3 is an enlarged sectional view taken on line liI--III of Fig. 2;and

Fg. 4 is a chart showing a number of characteristic operating curves.

Referring to the drawing in detail, especially Fig. 1, there is shown agas turbine engine 1i) equipped with a fuel pump 12 of the turbine type,formed in accordance with the invention.

The gas turbine engine 10 forms no part of the invention and has beenshown merely to illustrate a typical Y application for the pump. In theexample shown, the

' gas turbine engine is of the vwell-known axial flow aviation turbojettype having a tubular outer casing 13 within which are disposed an axialow compressor 14 having a rotor 15, fuel combustion apparatus includingan annular combustion chamber 16 equipped with a plurality of fuelinjecting nozzles 17, and an axial ow gas turbine 1S having a rotor 19drivingly connected to the compressor rotor 15 by a drive shaft 20. Thecasing 13 denes a forwardly directed air intake opening 21 and arearwardly directed exhaust nozzle 22.

In operation, fuel is admitted to the fuel injecting nozzles 17 by adelivery conduit 23 and injected into the combustion chamber 16 Where itis ignited in the presence of pressurized air to provide -hot motivegases for the turbine 18. After partial expansion in the turbine todrive the turbine rotor 19, the gases yare ejected through the exhaustnozzle 22 in -a rearwardly directed propulsive jet. The turbine rotor,in turn, drives the compressor rotor 15, whereby atmospheric air isdrawn through the air intake 21 and delivered in a pressurized state tothe combustion apparatus to complete the cycle.

The fuel pump 12 is provided with an impeller 25 having a pair ofannular rows of circumferentially spaced radial blades 26 and a housing27 tting snugly about the impeller and jointly therewith defining anannular duid pressure developing chamber 28 of symmetrical shape. Theimpeller 25 is carried by a rotatably supported drive shaft 29 which isdrivingly connected to the turbojet engine rotor aggregate by gearing3G.

Hence, the impeller 25 is rotated at varying speeds as determined by thespeed of the turbojet engine, in one direction, for example, clockwise,as illustrated.

'Ehe housing 27 provides a primary suction inlet 31, connected to asuitable fuel supply source 32 by conduit 53, and a primary dischargeoutlet 34, connected to the engine fuel delivery conduit 23. Thedischarge outlet 34 is peripherally spaced Ifrom the suction inlet 311to a large angular degree in the direction of impeller rotation, and inthe example shown, the angular spacing is about 250 degrees.

in addition thereto, the pump housing 27 is further provided withannular wall structure 35 deuing a bypass passageway 36, communicatingat its downstream end with the delivery conduit 23, and at its upstreamend with a secondary discharge outlet 37. Extending through the bypasspassageway 36 is a hollow strut 33 controlling the' secondary suctionintake 39 and the second-v ary discharge outlet 37, respectively. Thevalves .41 and 42 are formed lin such a manner that when they are de#energized their valve members 43 andi 44 are disposed in the iiowblocking position, as illustratedingFig. 1, thereby preventing fuel flowinto the suction intake 39 and from the discharge outlet Y37. Hence,with thevalves'in this position, the fuel from the supply conduit33VflowsV through the'primaryV suction intakecfl into the pump chamber 28and traverses an angular path'o 31361113250 de'- grecs before ejectionthroughthe: primary dischauge outlet 34. Y

The solenoid valvesV 414 and 412! are;controllori by an responsive ftothe rotational speed ofthe impeller shaft 2?. The speed responsiveswitch 46 is'connected into defining a secondary suction intake 39.Ther-secondary l relatively low fuel ow rates Yin the low speed rangeand considerably higher fuel Vflow rates inthe upperVA speed range, thefuel pump will satisfactorily fulfillV the Vfuel demands of the engine.Y

The following morespecic analysis serves, to more 2,940,394 Y Y l 1`fullyY outline the performance characteristics of the fuel pump forvarying operationofsthe turbojet'engine 10.

The turbojet engine 10for example, may have the followingrepresentativefuelr pressure and fuel consumption requirements, as shownin the .chart 'in Fig. 4. Y

Y in', the upper. speed .range,. betweenidling andrated' speed, the fuelrequiremcnts'fofatheengnieareillustratecf .by thecurveA.

,electricalcontrol Ysystemincluding a suitable'syvitch 46 theVelectrical system in series withrva suitable source Vof Y EME. 47andthesolenoid valves 41 andr42rare connected in'parallel. Also,ifrdesired, armanual'ly operable-switch Y sa may be provided forconditioning vthe systeni'for automatic operation-when desired. Thespeed responsive switch 46 isarranged ina mannerto. interrupt thecircuit.

through the solenoid valves 41 and V42st impeller shaft thelcircuitupon` attainment of the selected, speed by the shaft. Hence, when theengineglOis operating at a speed `speeds below a preselected'speed'valve andto complete i below the selected -value (low speedrange); thefuel Y pump isconditiorned as illustrated in Fig. 1, Whereas above lsaid selected value (upper Vspeed range)'the' solenoid valves 41 and 42Vare energized and' their, valve meni-V bers 43 Vand 44, respectively,are moved to the unblocking l position as illustrated in Fig. 2; l Y

When'the fuel pumpis conditioned'as Ishown kin Fig. 2, fuel from thefuel supplyis directedV through -thesupply conduit 33 to lthe fuel pumpthrough tthe primary suction inletand 'by the conduit 4t)Y through thesecondary inlet 39. Hence, the fuel admitted to the fuel pump'throughthe primary suction inlet 31 isY translatedV throughgthe pressuredeveloping chamber 28 inV an arcuateV path of about 90 degrees rand isthen ejected from the chamber through the secondary suctionV outlet 37.This fluid stream Y is .then directed through ythel bypassApassagewayY36 to the'fuel delivery conduit'. 23.

Accordingly, in therlo-w speed rangefor the.turbojet engine, withtthespeed responsive-switch 46 in the circuit interrupting positionaudr themanual switch 4S inV either the open or closed position, the fuelis fedto the in a like manner, the fuel admitted to the chamber 28 through thesecondary suction.

rfuel ilow rate.

BY ful'her referenceftothefchartashnwn; invFig.. 4, curve. B ilustratesthe low speed rangeefuel pumping. characteristicsv of the lfuel pump,withthe: solenoidxvalves 412 and 42 in theowblokngposition.. Curve-Brisesrather sharply and at .about ri400, rpm.; the 'pjumpdischargepressure is about 'p.s.i. While'atabout-,SOOO r.p.m. thepres-V sureisabout 675 p.s,i. Since-the l400'r.'-p.m. coincides with the startingr.p.m. of the engine, itf will be vnoted that' the pump discharge isVadequate to satisfy the engine fuel .pressure requirements in thisrrange; However, at 5.000 r.p.rn., coinciding withtheengineidlingspeedrthe pump pressure is considerably,abovethatrequired bythe engine. A'

Curve C' illustrates the... upper speed. rangefuel `pumpingcharacteristics voi" tliefueLpumgWiththe valvesin the unblockingposition.. It willfbeseen thatvvhenithe speedresponsivefsvvitoh.46'encrgizesthetvalves41 and'42. to theunblockillgposition, as'` indicated Aby vertical. dotted line D, the .pressurervalue dropsgto, about 100 p.s.i. but

the fuel flow rate of`770'ppzh. is. maintained'.y during suchv changeVin conditioning of tlie'pump. .Thereaften as the rpm. of the impellerincreases, the fuel pressure againr4 rises ina gradual manner withconcomitantrincreasefin Y By comparing-curves B land-Cwiththeengine'requirements mentioned above and curve"A,'i`treadily be seenthat the Vfuelfpurnp iscapable offsatisfying the engine fuelrequirementsinthe lovv as vvelljasrtheupper speed range. Also, intheupperspeed range, the fuelpressure` at the .pump outlet is maintainedat reasonable; yetA not excessively high, values above thed enginerequirements.

It will now be seen that'thefinv'ention providesa'highly i improved andversatile pumpoftleturbineitypevwhichl` may be reliably' employedas@ themainY fuel. pump 'of-1 a fnei combustion engine, such asaturbojetfengine. l

lt will further be4 scena-'that'.theeinventgionfprovides a turbine -typefluid pump having.` dualV liowV and pressure? outputcharacteristics'fwhich lends itself *to applicationsV engine aftertraversing theV fuel pump chamber 2 8 in one Y single path of largeangular extent, so that although the fuelztlow rateY is moderate, thefuel pressureis relativelyV high. p

in the upper speed range; wherein thespeederesponsive Vswitch 46 is inthe circuit making position, with` thev manual switch l48 inthe closedposition, the fuel is de-.

livered to the engine aftertraversing the fuel pump charnber in twoseparate streams through angulargpaths of individually less,V extentthan theV first Vmentioned. path.

Hence, the'fu'elflow .rate fis'considerably higher vvhileY the'fuelpressure value is reduced in proportion.

Since, as Well knovvnfin the -art,th e engine; 191dernandsj f extendingblades, housing structure surrounding .saidim-- wherein-it is driven;atvariable: speedthrough a relatively wide range of speed-sf While vtheinvention ehasibeerr shown'ixn butione form,

it will be obvious tothosefskilled vin'theuartthat it notv so limited,Ybut is susceptible,.of;various;.changes and'.

modic'a-tions without,Y departingfrmnif the; spirit thereof.Y

`What is claimedfis: f Y l. ln combination, apump comprising .animpellersofY the turbine type having aci-rcumferential-roweofradiallypellerand jointly Ytherewith deningan annular uidpres#Ysurizing chamber, saidY housing structure-defining a first suctioninlet; and `a first discharge ouden', asecondl suction:

inlet and a seconddischargeoutlet; said inlets'and out- Vletscommunicating directlywith. said chamber, means forv diiving saidimpellerviny onefidiljection at varyingspeeds.

of rotation, said first inlet and outlet being angularly displaced inthe direction of rotation to a greater degree than said second outletand inlet, valve structure for blocking and unblocking said second inletand outlet, and means responsive to speed of rotation of said impellerfor controlling said valve structure, said speed responsive means beingeffective to maintain said valve structure in the blocking positionbelow a predetermined speed and to move said valve structure to theunblocking position above said predetermined speed.

2. In combination, a pump comprising an impeller of the turbine typehaving a circumferential row of radially extending blades, housingstructure surrounding said impeller and jointly therewith dening anannular iluid pressurizing chamber, said housing structure delining afirst suction inlet and a first discharge outlet, a second suction inletand a second discharge outlet; said inlets and outlets communicatingdirectly with said chamber, means for rotating said impeller in onedirection at varying speeds, said first yinlet and outlet beingangularly displaced in the direction of rotation to a greater degreethan said second outlet and inlet, valve structure for blocking andunblocking said second inlet and outlet, and means responsive to speedof rotation of said impeller for controlling said valve structure, saidvalve structure being biased in a direction to block said second inletand outlet, and said speed responsive means being eiective to move thevalve structure to an unblocking position in response to a predeterminedspeed.

3. ln combination, a uid pump comprising an impeller of the turbine typehaving a circ xferential row of radially extending blades, means fordriving said impeller in one direction at varying speeds of rotationincluding a low speed range and a high speed range, housing structuresurrounding said impeller, said housing structure and said impellerjointly defining an annular fluid pressurizing chamber, said housingstructure further dening a rst suction inlet, a rst discharge outlet, asecond suction inlet and a second discharge outlet, all of said inletsand outlets directly communicating with said chamber; said iirst inletand outlet being angularly displaced in the direction of rotation ofsaid irnpeller to a greater degree than said second outlet and inlet,said second outlet being disposed upstream of said second inlet relativeto fluid ilow through said chamber, valve structure for blocking andunblocking said second inlet and outlet, said valve structure blockingsaid second inlet and outlet said low speed range, and means responsiveto speed of rotation of said irnpeller for jointly controlling saidvalve structure, said speed responsive means being eective to move saidvalve structure in unblocking ldirection in response to a predeterminedspeed, in said high speed range.

4. In combination, a fluid pump comprising an impeller of the turbinetype having a circumferential row of radially extending blades, ahousing enclosing said impeller and jointly therewith defining anannular iluid pressurizing chamber, said housing having a main suctioninlet and a main discharge outlet, said yhousing further including wallstructure dening an arcuate flow passage disposed externally of saidimpeller and communicating with said main discharge outlet, meansdeining a secondary suction inlet communicating with said impellerintermediate said main inlet and outlet, said housing providing asecondary discharge outlet communicating with said ow passage,electrically actuated valve structure for blocking and unblocking saidsecondary inlet and outlet, means for driving said impeller at varyingrates of rotational speed, and

means including a switch responsive to speed of Said driving means forjointly controlling said Valve structure, said switch means beingoperative to eect movement of said valve structure from the blockingposition to the unblocking position above a predetermined speed, therebyto increase the fluid ilow rate and decrease the iluid pressure at saidmain discharge outlet.

5. In combination, a iluid pump comprising an impeller of the turbinetype having a circumferential row of radially extending blades, ahousing enclosing said impeller and jointly therewith deiining anannular uid pressurizing chamber, said housing further defining a mainsuction inlet and a main discharge outlet communicating directly withsaid chamber, wall structure defining an arcuate ow passage disposed inbypass relation with said chamber and communicating with said maindischarge outlet, means deining a secondary suction inlet communicatingdirectly with said chamber intermediate said main inlet and outlet,means defining a secondary discharge outlet connecting said chamber andsaid flow passage, said secondary outlet being disposed intermediatesaid primary and secondary inlets, electrically actuated valve structurefor blocking and unblocking said secondary inlet and outlet, means fordriving said impeller at varying rates of rotational speed, and meansincluding a switch responsive to speed of said driving means for jointlycontrolling said valve structure, said switch means being operative toeect movement of said valve structure from the blocking position to theunblocking position above a .predetermined speed, thereby to increasethe `fluid ow rate and decrease the fluid pressure characteristics ofthe pump.

6. ln combination, a iluid pump comprising an impeller of the turbinetype having a circumferential row of radially extending blades, ahousing enclosing said Iimpeller and jointly therewith dening an annularfluid pressurizing chamber, said housing having a main suction inlet anda main discharge outlet, said housing further including wall structuredefining an arcuate ow passage disposed externally of said impeller andcommunicating with said main discharge outlet, means defining asecondary suction inlet communicating directly with said irnpellerintermediate said main inlet and outlet, said housing providing asecondary discharge outlet communicatving with said ovv passage,electrically actuated valve structure for controlling fluid ow throughsaid secondary inlet and outlet, means for biasing said valve structureto the position blocking said secondary inlet and outlet, means fordriving said -impeller at varying rates of rotational speed, and means.including a switch responsive to speed of said driving means forjointly controlling said valve structure, said switch means beingoperative to effect movement of said valve structure from the positionblocking said secondary .inlet and outlet to the position unblockingsaid secondary inlet and outlet at a predetermined speed and to maintainsaid valve structure in the unblocking position at speeds above saidpredetermined speed, thereby to increase the fluid flow rate anddecrease the duid pressure at said main discharge outlet.

References Cited in the le of this patent UNITED STATES PATENTS wrightJuly s, s

UNITED STATES PATENT OFFTCE @ERTIFICATE 0F CRBECTIUN Patent No 22&194O394 June 14V 1960 Garrett Eo Mesure t is hereby certified thaterror appears in the printed specification o the above numbered patentrequiring correction and that the said Letters Paten-t should read ascorrected below;

Column 5l line 47g after E'outletm insert we in we Signed and sealedt'he 25th dey of April lQL (SEAL) Attest:

ERNEST Eu SWTDEE DAVID Le LADD ttesting Ocer I Commissioner of Patents

